Tuesday, December 17, 2013

Happy Holidays! Who loves a Christmas tree decoration? And has broken one in their lifetime?

Well, in the real world, we get to see LIVING glass (or sometimes chalk) boxes that might pass for ornaments! But you need to shoot electrons at them to get something like a similar effect! Scanning Electron Microscopes are the gift that keeps on giving!

Here is a diatom called (appropriately) Skeletonema. This one occurs in Florida waters..Image by FWC-Fish & Wildlife Research Institute

Here's a nice image of Astropecten indicus from Singapore, illustrating the animal next to the star-shaped impression it makes in the sand.

Image by Kok Sheng

Here is an excellent photo sequence of a species of Astropecten from Iran, showing a full range of sitting on the sand and burying itself.

Image by Hamed Saber

Burial in Astropecten can be quite rapid. It accomplishes this via a combination of its pointed (rather than suckered) tube feet in conjunction with its many spines which are moveable and are used to help push itself into the sand. Astropecten is among the fastest of known starfish.
Image below of an Astropecten from Singapore.

Image by Wildsingapore.

Pictures are nice. But why stop there? Here's a quick 30 second video of Astropecten from Singapore burying itself and vanishing before your very eyes!

Which famous Simpsons gif meme does Astropecten remind you of?

This one is probably one of the best videos of Astropecten burying and reburying itself. A video from the Enoshima aquarium of A. polyacanthus.

Although they dig, they are not, strictly speaking, infaunal. They live buried right under the surface of the sand...

image by Bill & Mark Bell

Where, they are often digging through the sediment trying to find goodies to eat, such as this clam. But really whatever they find, they will swallow and devour. Note that Astropecten and its relatives LACK an eversible stomach (that you might see in other starfish). So they literally can ONLY swallow their prey.. This image is fr. A. aurantiacus in the N. Atlantic somewhere..

As I mentioned, Astropecten occurs widely around the world. And is quite diverse. Here is Astropecten articulatus from Georgia (south coast of the US)

Image by Alan Cressler

Astropecten sp. from Singapore. Cool racing stripes!

Image by Wild Singapore

Here's a pic of Astropecten latespinosus from Japan

Image by Yoichi Kogure!

The substrate/sediment type can vary also.. Some live in very fine sediments, such as this Italian Astropecten, possibly A. irregularis

Image by comunerimini

Astropecten aurantiacus in sandy sediment...

Image by Archipelagos Institute of Marine Conservation

Whereas others live in fairly coarse, sandy type sediments.. such as this Astropecten bispinosus from Greece.

Image by sarsifa

Astropecten sp. Not sure where this was taken..I think the Mediterranean? But again, coarse sediment.

Image by Dimitrious Poursanidis

Image by Dimitrious Poursanidis

What's that you say? You wanted to see more fabulous video of Astropecten from around the world burying themselves in sand? YOU GOT IT.

Wednesday, December 4, 2013

December Greetings! As we get into the holiday and Christmas season, I always get certain questions which pop up around this time of year, asked by the public. One of the common ones I receive around now is (paraphrased)

"Where do those starfish and sand dollars on holiday decorations come from?" Usually followed by "Are they alive?" and etc...

So, let me take a trek through several recurring photos of holiday decorations and show you species by species how they compare.

A general rule about echinoderms used in decorations: WHAT YOU SEE ARE NOT SHELLS, THEY ARE MUMMIES (dried endoskeletons).

Image by Werner Wittersheim

A bit of a refresher on basic echinoderm anatomy. All of the distinctive features one sees in echinoderms- spines, tubercles, the various shapes and etc. are covered by epidermis, in other words, SKIN.

So, yes, in order to get one of the starfish dried and made into a wreath? It has to be killed. (that's one of the questions I get about these by the way...)

So unlike say, shells which are secreted outside or independently of the animal's body, echinoderms have an internal support that is analogous to the skeleton in vertebrates. Their tissue is actually infused into this skeleton.

I've said this before many times. Here and here. I've always found the whole concept of putting echinoderms onto holiday decor as kind of macabre unless you're that guy who puts dead, dried frogs on your Christmas tree, which is perfectly fine....

1. "Knobby Starfish" Holiday Wreath

This is one, I've been seeing around is adorned with large, "Knobby Starfish"

These are Protoreaster nodosus, a species which occurs in the Philippines, Singapore, and all throughout the North-Central tropical Pacific.

Image by Ria Tan (Wild Singapore)

Image by Pau Estrada

Protoreaster nodosus is an abundant and easily encountered species where it occurs. It is harvested in several places for tourist and gift making decor. A whole industry is oriented around fixing (ie treating with formalin), drying and exporting dried starfishes. I've briefly discussed this here and here

2. Pisaster ochraceus & the "Coastal Wreath"(thanks to Gail for the tip!)

Thanks to the wonders of the Internet and directed marketing, I clicked on the link to this item ONCE. And it now shows up on ALL of my social media and other shopping pages...

The picture actually shows up on several different gift and other sites, which I'll decline to name. But two species are observered here. the starfish is Pisaster ochraceus aka the Ochre Star from the Pacific NW coast and the sand dollar Mellita (prob. Mellita quinquiesperforata ).

Its not unusual for Pisaster to turn up dressed up as any number of awful, tacky holiday decorations

Here again, is a pic of the animal alive to remind you of the contrast...

Another commonly encountered species in holiday decorations. Sand dollars, especially these species have the most "benefit of the doubt" because its not unusual to encounter their dead skeletons as beach wash.

Although one has to wonder how much collecting one needs to have enough to create a regularly marketable wreath such as the ones I've been seeing marketed on the Internet...

I'm pretty damn amazed at just how WIDESPREAD these get via the tourist industry. I've literally seen these sand dollars shipped across the country and across the WORLD for sale at tourist shops.

Here is what they look like with all the original spination and such...

and we even got video!

5. Echinometrid? "Sea urchin tree"?

Maybe Echinometra from Australia? Not sure. Like sea urchins, the tests can be gotten as beachwash.. but not regularly. So, I'm thinking these were likely harvested...

Image from NOAA photo library

The websites for "urchin trees" and such were running these items for anywhere between 70 to 150.00. But cripes! 150 dollars for sea urchin tree???

So to recap:
1. Starfish decorations are mummified remains of living animals, which had to be killed in order to get you a holiday wreath. I wouldn't lick them.
2. Many of the species used in these industries from the tropical Pacific are probably not sustainable fisheries.
3. Personally, I just think decorating starfishes like Santa Claus is tacky. So, please. just stop. Use sea shells or give people candy. People like candy.
4. Sand dollars are okay. Still possible to kill them for use as decorations. But also possible that they were collected beachwash.
5. Good grief. Who pays 150 dollars for holiday decorations made from beachwash??? or mummified starfish remains??? You know what's good for 150 dollars? chocolate.Send to the Echinoblog. Or charity. charity is good.

About Me

I pursue starfish related adventure around the world with a critical eye and an appreciation for weirdness.
Support has been courtesy of the National Science Foundation but the views and opinions presented herein are mine and do not reflect the opinions of them or any affiliated institutions.
Need to hire an invertebrate zoologist/marine biologist? Please contact me!